1) Field of this Invention
The field of this invention relates to mechanisms and more particularly to an arm mechanism which facilitates the moving of a tool located at the distal end of the arm mechanism with the movement of the tool being affected from the proximal end of the arm mechanism.
2) Description of the Prior Art
Robotic types of arm mechanisms have long been known. One common use for such an arm mechanism would be in conjunction with an underwater vehicle. The arm mechanism would be located exteriorly of the vehicle but operated by one of the occupants of the vehicle in a manned submersible or by an operator located remotely in the case of an unmanned vehicle. The arm mechanism could be used for picking up specimens on the sea floor or possibly accomplishing some type of work, such as repair of some form of underwater structure. Similar types of arm mechanisms are used in other environments such as nuclear reactors.
In the constructing of any arm mechanism certain objectives must be met in order to achieve a satisfactory arm mechanism. One of these objectives is that the arm mechanism must be positive in its operation. When commands are given at the proximal location of the arm mechanism to perform certain functions, those functions are to be performed at the distal location of the arm mechanism. In other words, let it be assumed that commands are given to operate a shovel at the distal location and a shoveling action to occur at a specific area of the terrain. The operative movements at the proximal end must result precisely in that shoveling action at the desired location.
Another objective is that fine control of the tool is required. In other words when it is necessary for the tool to make only small movements in a particular direction, those small movements can be made from the operating mechanism at the proximal location.
Another objective of an arm mechanism is that it should be operable over a wide arm range. Some arm mechanisms of the prior art can only operate over a very limited range and of course the greater the range of operability, the greater the versatility of the mechanism.
Another objective of such an arm mechanism is to have the arm mechanism manufactured at a reasonable cost. In the past such arm mechanisms have been manufactured at an exceedingly expensive cost which greatly limits their usage.